Question:
What exactly will happen when Moshiach comes?
Answer:
The Holy Temple will be rebuilt, the exiles will return, and Torah observance will be restored.
Maimonides states in his Mishneh Torah – a compendium of the entire halachic tradition – that Moshiach will first rebuild the Temple and then gather in the exiles. All the Jewish people from all ends of the earth will return to Israel. Jerusalem and the newly rebuilt Temple will be the focus of Divine worship and “From Zion shall go forth Torah, and the word of the L–rd from Jerusalem.”
The Sanhedrin – a supreme Jewish law court of 71 sages – will be established and will decide on all matters of law. At this time, all Jews will return to full Torah observance and practice. All nations of the world will also reach their perfection and will serve G-d with righteousness and justice. In the words of the prophet, "Then I will transform all nations to be pure of speech, to all call in the name of G-d and serve Him as one."
It should be noted that in this present age of great assimilation and emancipation, an unprecedented return of Jews to true Torah values has taken place. This “Baal Teshuvah” phenomenon is on the increase and paves the way for a full return to Torah observance in the messianic era.
Furthermore, our generation has also made inroads in influencing gentiles to observe the seven Noachide laws. Historically, Jews have been reluctant to share the Torah's teachings with gentiles, due to fear of persecution. Now, however, the gentile nations are demonstrating eagerness to hear the words of G-d, as they apply to their personal lives. This change, too, demonstrates that we are on the brink of a new era, when all the prophecies of redemption will be fulfilled.